Melt spinable concentrate pellets having enhanced reversible thermal properties

ABSTRACT

A process for manufacturing extrudable/melt spinnable concentrate pellets which contain phase change materials (PCMs), whether the PCMs are micro-encapsulated absorbed into carrier polymers, or non-micro-encapsulated within the concentrate pellets. The polymer matrix within the concentrate pellets can be any thermoplastic polymer or combination of thermoplastic polymers, and the concentrate pellets can then be blended into similar thermoplastic polymers to form mono-filament melt spun fibers, extruded films, injection molded products, etc., or the concentrate pellets can be blended with other thermoplastic polymers to form bi-component or multi-component melt spun fibers, extruded films, injection molded products, etc.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application claims the benefit of U.S. provisional patentapplication Serial No. 60/234,150, filed Sep. 21, 2000.

This application incorporates by reference the disclosure of thefollowing co-pending U.S. provisional patent applications, owned by theassignee of the present application: “Melt Spinnable Multi-componentFibers Having Enhanced Reversible Thermal Properties,” by Monte Magill,Serial. No. 60/234,410, filed Sep. 21, 2000 (now non-provisional patentapplication Ser. No. 09/960,591, filed Sep. 21, 2001; and “ThermallyStable Phase Change Material For Use In Temperature Regulating Fibers,Fabrics And Textiles,” by Monte Magill and Mark Hartmann, Serial No.60/234,149, filed Sep. 21, 2000 (now non-provisional patent applicationSer. No. 09/960,901, filed Sep. 21, 2001.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to the manufacture of melt spun synthetic fibershaving temperature regulation properties, the melt spun fibers beingformed from polymer-based concentrate pellets that have Phase ChangeMaterials (PCMs) therein.

2. Description of the Related Art

Many fabric materials are made from synthetic fibers. Two processes—awet solution process and a melt spun process—are generally used formaking synthetic fibers. The wet solution process is generally used toform acrylic fibers, while the melt spun process is used to form nylons,polyesters, polypropylenes, and other similar type fibers. A largeportion of the fibers that are used in the textile industry are made viathe melt spun process.

As is well known, nylon is a family of polyamide polymers characterizedby the presence of the amide group CONH; polyester fiber is a fiber inwhich the fiber-forming substance is a long chain synthetic polymercomposed of at least 85-percent by weight of an ester of a dihydricalcohol and terephthalic acid, and polypropylene (C₃H₅) is a syntheticcrystalline thermoplastic polymer having a molecular weight of about40,000 or more.

The melt spun manufacturing process generally involves passing a meltedpolymeric material or pellets through a device known as a spinneret, tothereby form individual polymeric fibers. The fibers are then made intoa filament/strand, or into a cut staple. After the fibers have beenformed, the fibers can be used to make non-woven material, oralternatively, the fibers can be wound into a yarn that is comprised ofindividual fibers, the yarn to be used thereafter in the weaving orknitting of a fabric material.

In order to provide a thermal regulation property to fabric materials,microencapsulated phase change materials (microPCMs or mPCMs) have beenincorporated into acrylic fibers that were made using an aqueous batch(solution) process. However, with respect to synthetic fibers that aremade by the melt spun manufacturing process wherein excessive amounts ofvolatile materials should not be present, conventional aqueous batchmethods for incorporating mPCMs into the fibers are problematic.

It is against this background that embodiments of the present inventionwere developed.

SUMMARY OF THE INVENTION

According to one aspect of the present invention, disclosed herein is aprocess for manufacturing melt spinnable concentrate pellets thatcontain Phase Change Materials (PCMs), but do not contain an excessiveamount of volatile materials. In accordance with this invention, thePCMs can be microencapsulated PCMs that are within the concentratepellets, the PCMs can be absorbed into carrier polymers that form theconcentrate pellets, and/or non-micro-encapsulated PCMs can be includedas a component of the concentrate pellets.

According to the invention, the melt spinnable concentrate pelletmatrix, or carrier polymer, can be any thermoplastic polymer or anycombination of thermoplastic polymers

Concentrate pellets in accordance with the invention, can be blendedinto similar thermoplastic polymers, and the blend can then be extrudedto form monofilament melt spun fibers, extruded films, injection moldedproducts, etc., or the concentrate pellets can be blended with differentthermoplastic polymers and the blend can then be extruded to formbicomponent or multi-component melt spun fibers, multi-componentextruded films, multi-component injection molded products, etc.

For example, polypropylene concentrate pellets that contain PCMs ormPCMs can be blended with an additional amount of the polypropylenepolymer and then melt spun to form polypropylene monofilament fibers, orthis same polypropylene concentrate pellet can be blended with, orbicomponent melt spun with, an amount of nylon polymer to formbicomponent polypropylene/nylon fibers.

In accordance with a feature of the invention, but without limitationthereto, a PCM(s), and preferably a microencapsulate PCM(s), in awet-cake form (i.e. in a water-based form) that comprises about 70weight-percent solids and about 30 weight percent water, is melt-blendedwith a low molecular weight dispersing-polymer, with the result thatabout all of the water that is within the wet cake is driven off as thePCM(s) is concomitantly generally uniformly dispersed throughout the lowmolecular weight dispersing polymer.

In this mixture of a PCM(s) and a low molecular weight dispersingpolymer, the dispersing polymer is selected for its compatibility with,and for its affinity for, the PCM(s), thus providing for an optimumdispersion of the PCM(s) throughout the dispersing polymer.

Granules of the above-described PCM/dispersion polymer are then meltblended with a high molecular weight polymer in order to produceconcentrate pellets of the invention that contain about 15 weightpercent of the PCM(s).

This high molecular weight polymer is selected for its affinity for thelow molecular weight polymer and for the physical qualities that aredesired of articles (i.e., fibers and the like) that are extruded, ormelt spun in conventional manners using the concentrate pellets of theinvention.

The foregoing and other features, utilities and advantages of theinvention will be apparent from the following description of preferredembodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1, FIG. 2, and FIG. 3 illustrate processes of making concentratepellets and other extruded products according to some embodiments of theinvention.

DESCRIPTION OF PREFERRED EMBODIMENTS

In accordance with the present invention, a process is disclosed formaking concentrate pellets of one or more polymers, each pellet havingone or more PCMs therein, the concentrate pellets being adapted for usein extrusion and melt spun manufacturing processes.

The concentrate pellet manufacturing process of this invention providesbenefits that are achieved by adding PCMs to products that aremanufactured using extrusion processes such as the melt spun process,non-limiting examples being fibers such as nylon fibers, polyesterfibers, polyethylene fibers and polypropylene fibers, films, andinjection molded articles.

The present invention forms concentrate pellets having enhancedreversible thermal properties, which concentrate pellets can then beused to make temperature regulating articles having PCMs therein, themelt spun fiber manufacturing process being an example.

The PCMs of the invention can be in a microencapsulated form wherein ahollow capsule or hollow shell having a diameter of from about 1 toabout 3 microns protects the PCMs that are within the capsule/shell fromexposure to the high temperature and high shear processing that iscommonly found in the manufacture of melt spun fibers and melt spunfiber components.

The PCMs of the invention can be contained within, surrounded by, orencapsulated within a number of polymer matrix formats, or withincarrier polymers, to thereby provide for the ease of handling of thePCMs, while at the same time, offering a degree of protection to thePCMs from the harsh environment of the extrusion/melt spin processingthe PCM-containing concentrate pellets, as well as protecting the PCMsthat are within melt spun fibers from subsequent fiber processing.

In accordance with the invention, raw or not-capsulated PCMs can beincorporated into a process by which the concentrate pellets of theinvention are manufactured. In this case, the PCMs are preferablyintroduced into the concentrate pellet manufacturing process via one ofthe late pellet manufacturing steps, to thereby minimize exposure of thePCMs to high temperature processing.

In one example of the invention, the PCMs are incorporated into any ofthe many process steps by which the concentrate pellets aremanufactured.

In another example, a wetflush process is used to form a plurality ofplastic-based granules, each granule containing mPCMs. Preferably,approximately 50 weight percent of a selected mPCM is placed in acompatiblizer plastic, and the PCM/plastic mixture is then ground downto form a plurality of granules, each granule containing mPCM. After thegranules are formed, concentrate pellets are formed from the mPCMgranules by adding a virgin thermoplastic polymer, to thereby reduce themPCM concentration within the finished concentrate pellet product. Inone example, the resulting concentrate pellets included about 15 weightpercent mPCM in relation to the thermoplastic polymer.

In accordance with a feature of the invention, the above-describedcompatiblizer plastic is a low molecular weight dispersing polymer, andthe above-described virgin thermoplastic polymer is a high molecularweight polymer, the low molecular weight dispersing polymer beingselected for its compatibility with, and for its affinity for, the mPCM,and the virgin thermoplastic polymer being selected for its affinity forthe low molecular weight polymer and for the physical qualities that aredesired of articles that are extruded or melt spun in conventionalmanners using the concentrate pellets of the invention.

Upon formation of concentrate pellets of the invention, the concentratepellets can be extruded/melt spun as is (for example, to producemonofilament fibers that contain about 15 weight percent of the mPCM),or the concentrate pellets can be blended with another polymer(s) andthen extruded/melt spun, for example, to produce multi component fibershaving, for example, from about 5 to about 10 weight percent of themPCM.

Finally, upon the formation of the PCM containing individual fibers asabove described, a desired fiber material, fabric material or textilematerial is formed. As described above, the individual fibers can thenbe used to manufacture a non-woven material, or the fibers can be usedby way of a yarn spinning process to manufacture fabric or textilematerials using a weaving process, a knitting process, or the like. Itis understood that the fiber/fabric/textile material that ismanufactured from the fibers is a matter of choice, and is not criticalto this invention. The manufactured fiber/fabric/textile material willcontain the above-described PCM, and as a result will exhibit thermalregulatory properties.

It should also be noted that the above-described concentrate pelletmanufacturing process is applicable to raw or un-encapsulated PCMs,wherein the PCM is placed into the concentrate pellets and theconcentrate pellets are then passed through an extrusion or melt-spunmanufacturing process to form extruded/melt spun articles such as fibershaving the PCM contained or held within a plurality of isolated volumesor spaces that are dispersed throughout the article

In accordance with embodiments of the present invention, concentratepellets can be manufactured using a variety of manufacturing processes;for example, 1) the use of mPCM containment systems, 2) the use ofgelled containment PCM systems, 3) the use of alternative containmentPCM systems, or 4) the addition of non-contained, raw ornon-micro-encapsulated PCM systems.

One such process for use with mPCMs involves wet flushing and/orsubsequent compounding of the mPCM into a thermoplastic polymer matrixor carrier. In one example, wet flushing consisted of the addition of adispersing-polymer into a heated mixing bowl and then melting thepolymer. Preferably, but without limitation thereto, thedispersing-polymer was a low molecular weight polymer. Upon melting ofthe dispersing-polymer, mPCM wet cake was slowly added to the moltenpolymer and permitted to disperse as, at the same time, water wasflashed or flushed off. Upon completion of the dispersion and theremoval of water, the dispersed mPCM/polymer concentrate was removed,cooled, and thereafter chopped into granules of acceptable dimensionsfor later blending.

The above-described dispersing polymer may include graft, homo, orcopolymers of polyolefins, polyamides, polyesters, or otherthermoplastic polymers that are compatible with, and have an affinityfor, the final polymer matrix of the melt extruded concentrate pelletproduct, which final polymer matrix is preferably a high molecularweight polymer matrix.

The above-described mPCM wet cake may consist of between about 1 and 90weight percent solids in water, and preferably contains between about 60and 70 weight percent solids. Final concentrations of the mPCM in thewet cake concentrate can be from about 30 to about 60 weight percent,and preferably it is from about 45 to about 55 weight percent.

To insure improved mixing in the final extruded concentrate pelletproduct, the wet flush concentrate can be further blended into thefinished product polymer matrix, to yield a concentrate pelletcontaining mPCM of about 10 to about 30% weight percent, and preferablyabout 15 weight percent.

PCMs can be gelled, absorbed or physically contained in a number ofways. One such means of gelling or physical containment is by theaddition of silica particles, fumed silica particles, zeolite particlesor absorbent polymers to the PCM to provide for ease of addition to theabove-described dispersing polymer.

PCMs that are physically contained can then be manufactured intoconcentrate pellets in a manner similar to the above-described process.One preferred method is by removing the above-described wet flushingstep and simply blending the PCMs with the dispersing-polymer, or withthe final matrix polymer of the concentrate pellet when the concentratepellet is extruded. This process yields concentrate pellets with PCMconcentrations similar to those described above; for example, from about5 to about 70 weight percent, and preferably about 15 weight percent.

PCMs that are not micro-encapsulated or otherwise contained can also beprocessed into concentrate pellets via the liquid injection of the PCMinto the concentrate pellet melt extrusion process, or by the co-feedingof solid PCM with the concentrate pellet's dispersing-polymer.

Liquid PCM can be thoroughly filtered and mixed to insure homogeneityprior to injection. Liquid injection of the PCM can occur at any time inthe pellet melt extrusion process, but preferably it occurs as late inthe process as is possible in order to insure adequate mixing and inorder to minimize exposure of the PCM to high temperature. By using thislate-stage PCM addition method, exposure of the PCM to high temperaturesand to any subsequent degradation or loss of PCM is reduced.

Solid PCM can be processed into concentrate pellets by simply co-feedingthe solid PCM and the pellet dispersing or matrix polymer resin into thefeed throat of the pellet melt extruder. Solid PCMs can also be sidestuffed into the pellet melt extruder in order to prevent feed throatplugging.

The above processes yield concentrate pellets having PCM concentrationsin about the 5 to 70% weight percent range, and preferably in about the15 to 25% weight percent range.

This invention provides temperature regulating benefits that areachieved by adding PCMs to synthetic articles such as fibers, films,foams and injection-molded members, which articles that are made byextrusion processes of which the melt spin manufacturing of fibers is anon-limiting example.

In accordance with this invention, at least one water-based PCM is addedto a melted dispersing-polymer that has an affinity for the PCM. Forexample, if the PCM comprises a plurality of individual PCM volumes,with each volume encased within a shell (i.e., a mPCM), then thedispersing polymer is selected so as to have an affinity for thematerial of which the shells are formed.

As this first melt is heated, the PCM is uniformly dispersed throughoutthe first melt, and the water is driven off of the first melt. Uponcooling, the resulting solid is mechanically processed, such as bypulverizing, to form granules that contain the PCM.

A second polymer, which can be called a matrix polymer, is then melted,and the above-mentioned granules are added to this second melt. Thissecond polymer can be called an article-specific polymer since it isselected to have an affinity for the dispersing-polymer, and to alsohave physical properties that are desirable for the final extrudedarticle.

Upon cooling of this second melt, the resulting solid is processes toform concentrate pellets. These concentrate pellets are then usable toform synthetic articles such as fibers, films, foams andinjection-molded devices by way of an extrusion processes; for example,synthetic fibers are made by way of a melt spin process.

A variety of polymers, homopolymers, copolymers or blends of thepolymers can be used as the matrix polymer. Non-limiting examples ofsuch matrix polymers are (1) polyamides such as Nylon 6, Nylon 6/6,Nylon 12, polyaspartic acid, polyglutamic acid; (2) polyamines; (3)polyimides; (4) polyacrylics such as polyacrylamide, polyacrylonitrile,and esters of methacrylic acid and acrylic acid; (5) polycarbonates suchas polybisphenol A carbonate, and polypropylene carbonate; (6)polydienes such as polybutadiene, polyisoprene, and polynorbornene; (7)polyepoxides; (8) polyesters such as polyethylene terephthalate,polybutylene terephthalate, polytrimethylene terephthalte,polycaprolactone, polyglycolide, polylactide, polyhydroxybutyrate,polyhydroxyvalerate, polyethylene adipate, polybutylene adipate andpolypropylene succinate, (9) polyethers such as polyethylene glycol(polyethylene oxide), polybutylene glycol, polypropylene oxide,polyoxymethylene (paraformaldehyde), polytetramethylene ether(polytetrahydrofuran), polyepichlorohydrin; (10) polyflourocarbons; (11)formaldehyde polymers such as urea-formaldehyde, melamine-formaldehyde,and phenol formaldehyde; (12) natural polymers such as cellulosics,chitosans, lignins, and waxes; (13) polyolefins such as polyethylene,polypropylene, polybutylene, polybutene, polyoctene; (14) polyphenylenessuch as polyphenylene oxide, polyphenylene sulfide and polyphenyleneether sulfone; (15) silicon containing polymers such as polydimethylesiloxane, and polycarbomethyl silane; (16) polyurethanes; (17)polyvinyls such as polyvinyl butryal, polyvinyl alcohol, polyvinylacetate, polystyrene, polymethylstyrene, polyvinyl chloride, polyvinylpyrrolidone, polymethyl vinyl ether, polyethyl vinyl ether, polyvinylmethyl ketone; (18) polyacetals; and (19) polyarylates.

The PCM may be dispersed in a variety of dispersing polymeric materials.Non-limiting examples of these dispering polymers include those listedabove, they may be homopolymers or copolymers, and they may vary inmolecular weight, functionality, and polymer chain architecture.Non-limiting examples include homopolymers of polyethylene,polypropylene, Nylon 12, polybutylene terephthalate, and copolymers suchas polyethylene-co-vinyl acetate, polyethylene-co-acrylic acid,polybutylene terphthalate-co-polytetramethylene terephthalate, andpolylauryllactam-block-polytetrahydrofuran.

High or low molecular weight materials may be used with lower molecularweight polymers being preferred for the dispersing polymer.

The functionality of the polymers can also be varied; for example, withthe addition of amine, amide, carboxyl, hydroxyl, esters, ethers,epoxide, anhydrides, isocyanates, silanes, ketones, and aldehydes.

The polymer architecture may also be varied, examples beinghomopolymers, copolymers, linear polymers, branched polymers, blockpolymers, star polymers, comb polymers, dendritic polymers, graftcopolymers and other combinations where branch arms or grafts may be thesame or a different homopolymer or copolymer, and branch arms or graftsmay be added in a controlled or a random manner.

EXAMPLE 1

As an example, about 5.0 pounds of a low molecular weight polyethylenehomopolymer (A-C16 polyethylene, drop point of 102° C., manufactured byHoneywell Specialty Chemical) was added to a wet flushing apparatus, andthe homopolymer was then slowly melted and mixed at from about 110 toabout 130° C. Once the entire homopolymer was melted, about 8.47 poundsof a mPCM wet cake (micro PCM lot# M42-31, 59.0% solids, manufactured byMicroTek Laboratories, Inc.) was slowly added to the molten homopolymerover about a 30 minute time period.

Water was flashed off as the mPCM disperse within the homopolymer.Mixing of the dispersion continued until less than about 0.15 weightpercent of the water remained (as measured using Karl-Fischertitration). The dispersion was then cooled and chopped for furtherprocessing, the chopped granules contained about 50 weight percent mPCM.

Melt spinnable concentrate pellets were then manufactured by dryblending about 30-pounds of the above-described granules with about70-pounds of a high molecular weight fiber grade polypropylenethermoplastic resin (Polypropylene homopolymer 6852 from PB AmocoPolymers).

The resulting dry blend was then extruded using a 2½-inch single screwextruder with all zones set at about 230-degrees C., with a screw speedof about 70 rpm, with 150 mesh screens, and with a nitrogen purge, thusproducing concentrate pellets of the invention.

The above-extruded extrudable/melt spinable concentrate pellets werethen oven-dried overnite at about 50-degrees C. and at about 1 mm Hg ofvacuum.

The concentrate pellets containing about 15 weight percent of mPCM, werethen extruded/melt spun at temperatures between about 230 and265-degrees C., and preferably at about 235 to 245-degrees C.

Filaments were spun/wound at takeup speeds of up to about 1600 metersper minute (mpm), and yielded from about 20 to about 6 deniers perfilament of melt spun fibers having a temperature regulatingcharacteristic with reversible thermal storage properties as wasprovided by the mPCM. Using Differential Scanning Calorimeter (DSC)testing, these fibers provided between about 17.5 and 23.2 J/g ofthermal energy storage capacity.

DSC Testing and Analysis

Differential Scanning Calorimeter (DSC) measurements of the above fiberswere made using a Perkin Elmer Pyris 1 instrument. Cooling wasaccomplished using a FTS Systems Intercoller 1. Data analysis wasperformed using a Perkin Elmer Pyris Thermal Analysis System andSoftware for Windows, version 3.72.

Test samples were prepared in Perkin Elmer hermetically sealed aluminumsample pans, and testing was performed while the test samples werecontinuously subjected to N₂ flow.

Test conditions consisted of 1) cooling the test samples to about minus10-degrees C., followed by 2) isothermal hold for about 1 minute atminus 10-degrees C., and 3) heating from minus 10-degrees C. to about50-degrees C. at a rate of about 5-degrees C. per minute, followed by 4)isothermal hold for about 1 minute at 50-degrees C., and then 5) coolingfrom 50-degrees C. to about minus 10-degrees C. at a rate of about5-degrees C. per minute.

While the methods disclosed herein have been described with reference toparticular steps performed in a particular order, it will be understoodthat these steps may be combined, sub-divided, or re-ordered to form anequivalent method without departing from the teachings of the presentinvention. Accordingly, unless specifically indicated herein, the orderand grouping of the steps is not a limitation of the present invention.

While the invention has been particularly shown and described withreference to preferred embodiments thereof, it will be understood bythose skilled in the art that various other changes in form and detailmay be made without departing from the spirit and scope of theinvention.

What is claimed is:
 1. A method of making polymer-based pellets thathave utility in extrusion and melt spun manufacturing processes,comprising: melting a dispersing polymer to form a melt; adding a wetcake of a phase change material to said melt to form a dispersion;heating said dispersion to reduce a water content of said dispersion;cooling said dispersion to form a solid; and processing said solid toform polymer-based pellets containing said phase change material.
 2. Themethod of claim 1 wherein processing said solid includes: blending athermoplastic polymer with said solid prior to forming saidpolymer-based pellets.
 3. The method of claim 2 wherein said dispersingpolymer is a low molecular weight polymer having an affinity for saidphase change material, and wherein said thermoplastic polymer is a highmolecular weight polymer having an affinity for said low molecularweight polymer.
 4. The method of claim 2 wherein said dispersing polymeris a low molecular weight polymer, and wherein said thermoplasticpolymer is a high molecular weight polymer selected from the groupconsisting of polyamides, polyamines, polyimides, polyacrylics,polycarbonates, polydienes, polyepoxides, polyesters, polyethers,polyflouocarbons, formaldehyde polymers, natural polymers, polyolefins,polyphenylenes, silicon containing polymers, polyurethanes, polyvinyls,polyacetals, and polyarylates.
 5. The method of claim 1 wherein saidpolymer-based pellets each contain from about 10 to about 30 weightpercent of said phase change material.
 6. The method of claim 1 whereinsaid wet cake of said phase change includes from about 60 to about 70weight percent of said phase change material.
 7. The method of claim 1wherein said dispersing polymer is a low molecular weight polymer. 8.The method of claim 1 wherein said dispersing polymer is a polyethylenehomopolymer.
 9. The method of claim 1 wherein said phase change materialis an encapsulated phase change material.
 10. The method of claim 1wherein said phase change material is physically contained by a materialselected from the group consisting of silica, fumed silica, and zeolite.11. The method of claim 1 wherein processing said solid to form saidpolymer-based pellets includes an extrusion step.
 12. The method ofclaim 1 wherein heating said dispersion includes heating said dispersionuntil said water content of said dispersion is less than about 0.15weight percent.
 13. The method of claim 12 wherein said polymer-basedpellets each contain from about 15 to about 25 weight percent of saidphase change material.
 14. A method of manufacturing polymer-basedpellets that are useable in extrusion and melt spun processes to formplastic articles, comprising: providing phase change material; providinga low molecular weight polymer having an affinity for said phase changematerial; providing a high molecular weight polymer having an affinityfor said low molecular weight polymer and having physicalcharacteristics compatible with an intended use of said plasticarticles; melting said low molecular weight polymer to form a firstmelt; generally uniformly blending said phase change material into saidfirst melt to form a first blend; cooling said first blend to form afirst solid; processing said first solid to form granules; melting saidhigh molecular weight polymer to form a second melt; generally uniformlyblending said granules into said second melt to form a second blend;cooling said second blend to form a second solid; and processing saidsecond solid to form said polymer-based pellets.
 15. The method of claim14 wherein said polymer-based pellets each contain from about 10 toabout 30 weight percent of said phase change material.
 16. The method ofclaim 14 wherein: said low molecular weight polymer is selected from thegroup consisting polyethylene, polypropylene, Nylon 12, polybutyleneterephthalate, polyethylene-co-vinyl acetate, polyethylene-co-acrylicacid, polybutylene terphthalate-co-polytetramethylene terephthalate, andpolylauryllactam-block-polytetrahydrofuran; and said high molecularweight polymer is selected from the group consisting of polyamides,polyamines, polyimides, polyacrylics-, polycarbonates, polydienes,polyepoxides, polyesters, polyethers, polyflourocarbons, formaldehydepolymers, natural polymers, polyolefins, polyphenylenes, siliconcontaining polymers, polyurethanes, polyvinyls, polyacetals, andpolyarylates.
 17. The method of claim 14 wherein said phase changematerial is an encapsulated phase change material.
 18. The method ofclaim 14 wherein said phase change material is physically confined to aplurality of physical volumes by a material selected from the groupconsisting of silica, fumed silica, and zeolite.
 19. The method of claim14 wherein processing said first solid and processing said second solideach include an extrusion step.
 20. The method of claim 14 whereinblending said phase change material into said first melt includes addinga wet cake of said phase change material to said first melt to form saidfirst blend, and the method further comprises heating said first blenduntil a water content of said first blend is reduced to less than about0.15 weight percent.
 21. The method of claim 20 wherein saidpolymer-based pellets each contain from about 15 to about 25 weightpercent of said phase change material.
 22. The method of claim 14wherein said phase change material is microencapsulated within aplurality of hollow shells, and wherein said low molecular weightpolymer includes a constituent having an affinity for said hollowshells.
 23. The method of claim 14 wherein said phase change material isencased in a plurality of nylon shells, and wherein said low molecularweight polymer includes a nylon constituent.
 24. The method of claim 14wherein blending said phase change material into said first meltincludes adding a water-based form of said phase change material to saidfirst melt to form said first blend, and the method further comprisesheating said first blend until a water content of said first blend isgenerally eliminated.
 25. The method of claim 24 wherein saidwater-based form of said phase change material is a wet cake of saidphase change material.
 26. The method of claim 25 wherein said wet cakeof said phase change includes from about 60 to about 70 weight percentof said phase change material.
 27. A method of manufacturingpolymer-based pellets that are useable in an extrusion/melt spun processto produce synthetic fibers, comprising: providing a water-based form ofa phase change material; providing a low molecular weight polymer havingan affinity for said phase change material; providing a high molecularweight polymer having an affinity for said low molecular weight polymerand having physical characteristics compatible with an intended use ofsaid synthetic fibers; melting said low molecular weight polymer to forma first melt; blending said water-based form of said phase changematerial into said first melt to form a first blend; heating said firstblend until a water content of said first blend is generally eliminated;cooling said first blend to form a first solid; physically processingsaid first solid to form granules; melting said high molecular weightpolymer to form a second melt; generally uniformly blending saidgranules into said second melt to form a second blend; cooling saidsecond blend to form a second solid; and physically processing saidsecond solid to form said polymer-based pellets.
 28. The method of claim27 wherein said polymer-based pellets each contain from about 10 toabout 30 weight percent of said phase change material.
 29. The method ofclaim 27 wherein said phase change material is encapsulated within aplurality of hollow shells, and wherein said low molecular weightpolymer has an affinity for said hollow shells.
 30. The method of claim27 wherein physically processing said first solid and physicallyprocessing said second solid each includes an extrusion step followed bya pulverizing step.
 31. The method of claim 27 wherein heating saidfirst blend includes heating said first blend until said water contentof said first blend is reduced to less than about 0.15 weight percent.32. The method of claim 27 wherein said water-based form of said phasechange is a wet cake of said phase change material.
 33. The method ofclaim 32 wherein said wet cake of said phase change includes from about1 to about 90 weight percent of said phase change material.